The Perfect "Signaling Device".... Traditionally, scuba divers have relied on whistles as their only signaling device in surfacing emergencies. But if a diver is disabled and can't blow into the whistle, the whistle makes no sound at all. Equally frustrating (and dangerous), if a diver needs to attract the attention of someone who is too far away to hear the whistle, the whistle is of no help. Or, what would you do if you wanted the attention of your dive buddy, for whatever reason, and they were simply distracted and not paying attention to you at that very moment? Traditionally, you would be forced to swim up to them until you got their attention. In contrast, Dive Alert Plus V2 enables divers with a mere squeeze of the unit to generate a loud blast of sound on the surface that can be heard up to a mile away! Or, for subsurface signaling the diver can now signal for his dive buddy's attention underwater! Dive Alert Plus V2 is a specially designed, small, light weight pneumatic signaling device that uses quick-connect/disconnect hose fittings to become an integrated part of your power inflator. Installation is easy and takes only a moment. Dive Alert Plus V2 does not require any modification of your other equipment, and it does not interfere in any way with the normal operation of your other equipment.